There is a lot of bitterness and some inaccuracies in the comments. This is overall a well done design and the patent doesn't step on the toes of existing laser printer manufacturers.

Interesting . But the laser is only active during 1/4 of the mirror rotation... If it is so great then why Trumpf, Raylase, Precitec and IPG are not using these yet...

The speed comparison in the video is between the CASA printer and the fastest SLS traditional printer. The technology will allow print speed faster by a multiplier of 165 times the fastest SLS printer in the market.

@CruzMonrreal

3 жыл бұрын

Do you have a source for that so that this comment doesn't come across as an employee patting themselves on the back?

@cbibas

3 жыл бұрын

@@CruzMonrreal. Science is the source: A top speed of a brushless motor is 200,000 RPM (f=3333.33 RPS). Using the present distance of 125 mm from M1 to M2 will be reflecting the beam at a speed V=2*PI*f*R-->V=1309 meters/sec. Can you imagine what the speed will be if we'll be using a distance of 500 mm?

Congratulations, seem you have got a patent using the same technic as a simple laser printer. Although with your design the printhead moves, not the paper.

@KeesHessels

3 жыл бұрын

Yea, i would not have any problems incorporating it in our products, just because these patents are pending or even granted, prior use is prior use.

@KeesHessels

3 жыл бұрын

besides the same principles are used in machines for ldi (exposing pcb's)

@tecnicalab3505

2 жыл бұрын

@@KeesHessels. In the ldi (exposing pcb's): Beam speed is limited to the actuator carrying the laser Beam speed is not delivering constant Energy; Energy density is not constant as a result. Imposing slow control. The use of lenses augment the laser focal point and add calibration complexity. MTBF - Mean Time Between Failure is short. Energy delivery to the surface is limited by the focusing lens. This should give you an idea why the two systems differ.

@KeesHessels

2 жыл бұрын

​@@tecnicalab3505 1. Beam speed is limited to the actuator carrying the laser, I guess you mean beam position ? the beam goes with the speed of light... pretty universal. so the actuator is a mirror on a motor. What is different in an ldi machine or laser printer or regular sla resin printer where the mirror is also mounted on a motor? 2. Beam "speed" (whats up with that?) is not delivering constant energy ? again how is that different from sla resin printers or ldi machines. there position is relative to the laser output power. in essence you compensate for travel but even if a beam has a slightly longer or shorter path, it has zero effect on the power at the focus point. the shape of the focal point would be something different but you are not mentioning that. 3. The use of lenses augment the laser focal point and add calibration complexity. what do you even mean by this ? especially since you say later on " Energy delivery to the surface is limited by the focusing lens" 4. MTBF What is your base of saying this ? numbers ? compared to what ? man, great that the market gains traction with more and new products, and i'm all for selling more of these machines but please lay of the whiskey , you offered not a single explanation for justifying your patent claim. stick to beer light...

@tecnicalab3505

2 жыл бұрын

@@KeesHessels, We are talking about the position where the laser beam hits the print surface and the speed at which that laser beam spot moves along the surface as the motor rotates. The difference between galvanometer printers and ours is: in the other printers, the mirror mounted on the motor reflects the laser beam directly onto the surface. With that geometry, the laser beam has to travel different distances to reach different points across the surface, so it cannot always stay in focus. Also, the angle at which the laser beam hits the surface will change as the spot moves across the print surface, which changes the shape of the beam cross-section on the surface. Furthermore, because of the geometry, even if the motor rotates at a constant speed, the speed at which the beam spot moves across the surface will vary, increasing as the spot moves away from the mirror. Our printer uses a combination of two mirrors to steer the beam across the surface. The rotating mirror reflects the beam onto a second, curved mirror that in turn reflects the beam onto the surface. The geometry of this setup ensures that the laser beam always travels the same distance to reach every point on the print surface and it always hits the work surface at a right angle. Also, the speed at which the beam moves along the surface is constant. These properties allow our printer to deliver consistent energy across the entire print surface. The laser produces a certain amount of power, which is energy per unit time. That energy is delivered to the print surface, spread out over the distance the laser beam moves along the surface in that unit time. If the beam spot is moving faster along the surface, it will cover a longer distance in that unit time and therefore the energy per unit area will decrease. The optics of the printer focus the laser beam at a certain focal length. If the distance the beam travels to the surface varies, it will not always be in focus when it hits the surface, so the size and shape of the spot on the surface will vary. When it’s out of focus, the power of the beam will be smeared out over a larger surface so the energy per unit area will be smaller. As explained above, our printer always delivers consistent energy density across the print surface.

Maybe you could scale like idex. Just stack multiple lasers and mirrors for more cost-effective build volume and redundancy.

Sacrificing isotropic uniformity for speed will always be concerning to some.

This is quite cool, working a lot like a laser printer or a copy machine's laser system. But one thing I'm wondering tho is the galvo system has the benefit of tracing out the outermost edges thus improving surface quality. Your system is essentially "scan-only", would the surface quality be comparable with a conventional one?

@cbibas

3 жыл бұрын

It is not comparable because our printer print much higher quality without the FOV (Field Of View) losses (more below). Traditional printers print with Errors related to the Galvanometer FOV. Therefore, addressing the effects and not the cause. We do not have Field Of View Errors. For more details, please read this study: www.researchgate.net/project/Effects-of-galvanometer-laser-scanning-system-on-structural-integrity-of-3D-printed-parts In regards to the Galvs tracing the outermost edges (contour). The Galvs tracing the contours to compensate for the heat loss resulting from the FOV losses and the unsintered neighboring powder. While Galvs energy absorbed by the surface is quantified by E0*Cos^4(FOV) the Galvs controller needs to recalculate the depositing energy as FOV is changing. In comparison, Tecnica3D does not have FOV errors, therefore Tecnica3D is compensating only for the neighboring colder power. This compensation is simple and is incorporated into the slicing algorithm where contour pixels will be receiving a higher level of energy. Therefore, the contouring can be done if needed. In short, although it is printing in a raster (curves), the contours pixels receiving more energy will be reflected in the same way as if it was a Vector print. In fact with this system we can do multiple contours or Vector printing at the time compares to Galvs.

@tecnicalab3505

2 жыл бұрын

The question to ask is: why a Galvanometer based system needs to trace the outermost edges. Answering this question will be revealing inconsistency in voxel energy delivery (especially at the edge of the print). In contrast, our system deliveres consistent power intensity to any pixel/voxel across the print area. Moreover, if needed, we can deliver higher energy intensity to any specific voxel. This capability gives us the ability to print vectors although we print in raster like method. This method enable us to print multiple vectors simultaneously. As an example lets assume that there are few cotutor corves in the model. We can specify higher intensity for all of the voxels on the contour curves. When the raster print takes place it is printing all contour vectors at the same time. In short, Tecnica3D system has a better heat stability compares to a Galvanometer based system. Here is a video illustrating why Galvanometer based print system is limited. kzread.info/dash/bejne/jKB20ZKbdty8Xaw.html

Well, there might be an interesting point in using such a scanner system that creates a telecentric behaviour so the the spot is always a circle instead of being distorted with the incident angle BUT there is some serious marketing BS in the video. It is up to debate whether the change of intensity even has an impact on the part or whether the energy absorption is the key factor. Because mind that a larger spot might have a lower intensity (which reduces energy absorption) but this is compensated by the longer time it takes for the bigger spot to pass over the same amount of material. In addition the fact that there is a much greater pause between scan vectors (where the rotating mirror passes the ~270° which don't cover the conical mirror) is completely neglected which might actually have an impact because of the material having more time to cool between two consecutive laser passes. And how on earth is this supposed to be nearly three times faster without changing the area to be exposed or the scan speed and laser power which would make the comparison completely pointless? Maximum scan speed is not limited by the physical capabilities of the scanner but by the material and thermal management.

@tecnicalab3505

2 жыл бұрын

Thank you for taking the time to comment on the Øgon system. I’ll address each of your points: POINT I “there is some serious marketing BS in the video. It is up to debate whether the change of intensity even has an impact on the part or whether the energy absorption is the key factor. Because mind that a larger spot might have a lower intensity (which reduces energy absorption) but this is compensated by the longer time it takes for the bigger spot to pass over the same amount of material. “ Answering POINT I If the beam spot distortion were completely within the path of travel of the beam and the beam traveled at a constant velocity, then you would be correct that the longer time for the spot to pass over a pixel would compensate for the reduced energy intensity. However, the spot distortion is not confined to the path of travel of the beam nor is the beam traveling at a constant velocity (the velocity increases with distance from the center of the print surface). And even with your assumptions, the pixels at the end of the print vectors would receive less energy intensity. But the key point is that a big spot (off focus) means that you are degrading the resolution you intended to print with. Additionally, the angle of incidence decreases (undesirable) the vertical heat vector and increases the horizontal heat vector (undesirable) Assuming you increase the energy to compensate by sitting on the pixel longer will introduce a new problem where more energy will spill sideways, rather than sinter the top layer to the previous layer it will sinter to neighboring pixels that were not intended to sinter in the first place. Additionally, metal printing (because of the high conductivity) is even more challenging. In short, a galvanometer mitigates, our system eliminates. On this note: when you buy a galvanometer based printer, you are paying mostly for the mitigation add-ons (Calibration Camera, Offset Calibration, Linearity Calibration, Machine Learning software, etc). POINT II “In addition the fact that there is a much greater pause between scan vectors (where the rotating mirror passes the ~270° which don't cover the conical mirror) is completely neglected which might actually have an impact because of the material having more time to cool between two consecutive laser passes.” Answering POINT II Always (with the galvanometer system as well), you have a pause between two vectors as two vectors cannot be printed at the same time. If your intention is to state that the delay between two vectors in our system is much larger than a galvanometer system. Then, the following should provide a definitive answer: kzread.info/dash/bejne/dGeY1s-OgcXIldY.html POINT III “And how on earth is this supposed to be nearly three times faster without changing the area to be exposed or the scan speed and laser power which would make the comparison completely pointless? Maximum scan speed is not limited by the physical capabilities of the scanner but by the material and thermal management.” Answering POINT III With galvanometers, maximum printing speed is limited by the issues discussed above. The larger spot size in galvanometers degrades the resolution and unintentionally heats up the area around the target pixel, causing “sideways” sintering. This constrains the maximum rate at which energy can be supplied to the material during the printing process. This is particularly problematic for metal because of its high heat conductivity. The pinpoint accuracy of the Øgon enables more precise thermal management of the material, making it possible to print considerably faster.

i dont see a difference here between this and a normal laser printer LSU unit.... The only difference is the LSU unit is much faster as it has multiple mirrors. if you replace the LSU motor controller you get a lot more than 1200 dpi resolution.....

@tecnicalab3505

Жыл бұрын

LSU is using polygonal scanner. Polygonal scanner can reach closer speeds to our system. However, LSU suffers from beam enlargement and changes of optical path length that are much worse than a galvanometer system. The following paper is a study published by SPIE where we compared the three systems (Galvanometer, Polygonal and the 0gon): C. Bibas, "Advances utilizing the Ogon, a Lens Free Optical Scanner (LFOS)," Proc. SPIE 12170, Advances in 3OM: Opto-Mechatronics, Opto-Mechanics, and Optical Metrology, 1217006 (5 May 2022); doi.org/10.1117/12.2600487

55 4vgx de 665

i do have exp on galvo ans that speed you say.. forget it.. you will be acurate if your X or Y axis will be 0,001 step.. (if) and well elimination of F-Theta is nice idea.. why i see no finished product?? 4year now.. and.. well nothing nothing..